I have the catalogs that R. V. Dewey listed in his quest for information on the 1855 set of Flying Eagle cents. There are no U.S. coins in the Bangs sales (2) listed for 6 - 17 - 1870. Both sales held by Bangs contained Greek and Roman coins. The Mason sale held on 6 - 17 - 1870 contained lot 364: "1855; complete set of Flying Eagle Cents; copper, brass, nickel, composition, etc.; proofs; as sets very rare; 8 pieces." It sold for 75 cents. The Steigerwalt sale on 5 - 21 - 1907 contained lot 1483: "1855. Cents. Flying Eagle. Six specimens, said to illustrate the various alloys, from copper to nearly pure nickel, in which they were struck. These are supposed to be from the Mint where used as samples. Five have very light marks, as III, IV, said to be the checks made at Mint. Two show trifling weakness in striking; others are dull proofs. 6 pcs." No prices on this lot.

I can supply the auction description from the Appleton/Stamm Collections (Charles Steigerwalt, 5/1907), lot 1483:

"1855. Cents. Flying eagle. Six specimens, said to illustrate the various alloys, from copper to nearly pure nickel, in which they were struck. These are supposed to be from the Mint where used as samples. Five have very light marks, as III, IV, said to be the checks made at Mint. Two show trifling weakness in striking; others are dull proofs. 6 pcs."

I have a copy of Steigerwalt's sale #62. It was the Appleton sale part 1. It is priced and the lot R. V. Dewey asked about was number 1483, which sold for $6.00.